When Doctor Who staged its big comeback in 2005, few people were more excited than Russell T. Davies, the series’ head writer and executive producer and a longtime Whovian who had spent years rallying the BBC to let him bring the landmark sci-fi series back. Though The Doctor’s second coming has been a hit since it first debuted, Davies recently revealed the one regret he has about "Rose," the revival’s first episode: that he didn’t call Rose a “tart.”

The scene in question occurs at about the 12:10 mark in the video below. It’s from "Rose," the episode that first introduces us to the Ninth Doctor (Christopher Eccleston) and his soon-to-be-faithful companion Rose Tyler (Billie Piper), who are being terrorized by a plastic arm (for reasons that require you to watch the whole thing to understand).

Though it has been more than a dozen years since the episode first premiered, Davies recently had the chance to revisit it when he wrote a novelization of the “Rose” script for BBC Books.

"It was actually hard work, I've got to be honest," Davies told Digital Spy of revisiting the series in prose form. “I kind of thought, 'This'll be a laugh!' and then as I sat down with an empty page and realized it had to be 40,000 words, the horror set in. After 1000 words, I was sitting there going, '39,000 more?!'—I was glad I was allowed enough time. It was great fun, though ... and it's kind of a kick up the arse for it as well."

It was during that process that a simple line occurred to Davies that he wished he had thought of back in 2005.

"[Rose's mom] Jackie Tyler finds Rose on the floor, on top of a broken coffee table with the Ninth Doctor, rolling around with a plastic arm ... and Jackie says, 'Rose Tyler— you tart!,’” he explained of the reimagined version.

"Why didn't I think of that in 2003? Why? I love that line. I literally sat there banging my head going, 'That's the end of that scene!,' because if you watch that scene [on television], it just kind of ends ... so you go, 'That's it, she comes out the bedroom and finds them, rolling on the floor!' Brilliant! So little moments like that were a joy.”

Davies isn’t the only Doctor Who writer who has been tapped to novelize a script for BBC Books's "Target Collection"; the latest installments include Paul Cornell's rendition of “Twice Upon a Time,” the 2017 Christmas special that gave viewers their first glimpse of Jodie Whittaker as the Thirteenth Doctor, while Steven Moffat is tackling “The Day of the Doctor,” which saw the Tenth and Eleventh Doctors (David Tennant and Matt Smith) team up for a 50th anniversary special.

“I was very envious of Steven," Davies admitted of Moffat’s assignment. "I was very happy with what I'd done, and then I read Steven's and I thought, 'Oh, mine's just set on a council estate and a shop.' At most, the Southbank! He's on Gallifrey and back in history with Elizabeth I and there's the Time War … I would've loved to have written that.”

[h/t: Digital Spy]